Monday, 15 February 2016

NEJM Week of 21st January 2016 (#26)

Professor Brian Andrews NEJM Recommendations
for Medical Students and Tutors
Week of the 21st January 2016 (#26)
University of Notre Dame Australia
(Fremantle Campus)

Occasional Editorial Comment
None

MUST READ SECTION
CLINICAL PRACTICE

Postmenopausal Osteoporosis

http://www.nejm.org/doi/full/10.1056/NEJMcp1513724

Management of postmenopausal osteoporosis includes non-pharmacologic treatment (e.g., weight bearing exercise and fall-prevention strategies) and pharmacologic treatment. Bisphosphonates are considered first-line treatment in most women; benefits and rare potential risks are discussed.

This is an excellent review of the current management of postmenopausal osteoporosis with extensive current bibliography and an evidenced based discussion which is easy to read. Students should keep this link for the future.

Recommended learning:
1.     Causes, diagnosis and treatment of osteoporosis
2.     Falls in the elderly

Articles Recommended for Medical Students

ORIGINAL ARTICLE

CDX2 as a Prognostic Biomarker in Stage II and Stage III Colon Cancer

CDX2 is expressed in most colon cancers, but approximately 4% do not express this transcription factor. Lack of CDX2 expression marks a subset of cancers with a more aggressive natural history. Adjuvant chemotherapy primarily benefits patients with stage II CDX2-negative tumors.

EDITORIAL

Prognostic Subgroups among Patients with Stage II Colon Cancer



This is an interesting paper which highlights one of the ways that genetic markers, or in this case the transcription factor CDX2, can be utilized to direct specific therapy in patients with colon cancer.
In patients with colon cancer (not rectal), the therapy for stage I disease (surgery alone) and stage III disease (surgery + adjuvant chemotherapy) are generally well established. The question arises with the management of Stage II disease: which patients would benefit by the addition of chemotherapy and which patients do not need chemotherapy and its attendant adverse effects?
This article attempts to provide an answer to this question by measuring the presence or absence of nuclear CDX2 by both immunohistochemical and microarray analyses in colon cancer specimen of patients with stage II disease. Most colon cancers express nuclear CDX2 but a minority (5-7%) fail to express this marker. It is the latter group who have a higher recurrence rate after surgery alone and their five year survival with chemotherapy can be increased from 56% to 91%, highlighting the use of a marker to predict a poorer outcome and to improve survival by the addition of adjuvant chemotherapy.

 

IMAGES IN CLINICAL MEDICINE

Taenia saginata Infestation

http://www.nejm.org/doi/full/10.1056/NEJMicm1504801

A 38-year-old man presented with worsening abdominal pain, vomiting, anorexia, generalized weakness, and weight loss that had begun 3 days earlier. He had a history of eating raw beef. Examination of stool showed an embryonated egg containing an oncosphere.

CASE RECORDS OF THE MASSACHUSETTS GENERAL HOSPITAL

Case 2-2016 — An 84-Year-Old Woman with Chest Pain, Dyspnea, and a Rash

http://www.nejm.org/doi/full/10.1056/NEJMcpc1502149

An 84-year-old woman was admitted to the hospital because of chest pain, respiratory distress, and a purpuric rash. Initial chest imaging showed bilateral patchy and confluent opacities, a finding consistent with pulmonary edema. A diagnostic procedure was performed.

 

This is a discussion of an interesting systemic disease presenting with purpura and extensive ecchymoses: the latter are not only palpable but associated with the characteristic and diagnostic yellowish infiltrate and capillary instability. On bedside teaching last year, we saw a patient with this disorder and a monoclonal antibody against coagulation factor VIII. Review the echocardiographic findings in this disorder.



Important Articles Related to Mechanisms of Disease and Translational Research

CLINICAL IMPLICATIONS OF BASIC RESEARCH

Kindling the Kidney

Investigators have generated kidney-like organoids — complete with nephrons, collecting ducts, stroma, and vasculature — from induced pluripotent stem cells.

This is a fascinating 2015 study by Taguchi et al in Cell Stem Cell where pluripotent stem cells are derived from individual skin epidermal cells and, by the addition of a specific growth factor cocktail, transforming these cells into three dimensional nephron organoids. I predict that in the next twenty years, transplant recipients will provide autologous stem cells from their own skin and these will then be used to generate their own renal transplant. But still, there is yet a long way to go. The reviewer indicates that even now, these preparations could be used to screen for the nephrotoxic effects of new and current drugs and also obtaining organoids from patients with genetic kidney disease to determine pathogenetic mechanisms and test new therapies.

Recommended learning:
1.     Review the types of stem cell used in transplantation
2.     Review the structure and function of the nephron

Other areas which should be of interest to medical students
ORIGINAL ARTICLE

Mutations in TUBB8 and Human Oocyte Meiotic Arrest

Mutations in a tubulin gene caused infertility due to oocyte arrest in about a third of families tested. The investigators found that the mutant tubulins wreak havoc on microtubule assembly in the oocyte.
EDITORIAL

Exacting Requirements for Development of the Egg

The hallmark of successful human reproduction is the fusion between a haploid spermatozoon and a metaphase II oocyte. The generation of such an oocyte involves a series of steps whereby germinal-vesicle oocytes (in which the nuclei are intact) at prophase I are stimulated to resume meiosis and mature to metaphase II, a sequence of events that prepares the oocyte for fertilization.

The Editorial provides an excellent Figure demonstrating the meiotic maturation of human oocytes. Further, the mutations described in TUBB8 producing meiosis I oocyte arrest would be recognised by the absence of the first polar body in patients undergoing IVF. We await the description of further genetic mutations. The science is amazing.

Perspective
HISTORY OF MEDICINE

Regulating Homeopathic Products — A Century of Dilute Interest

http://www.nejm.org/doi/full/10.1056/NEJMp1513393

 

In 2015, U.S. government agencies began considering greater regulation of both homeopathic drugs and the advertising of such products. These actions came after more than a century of missed opportunities to regulate homeopathic medicines

 

This is an excellent history of homeopathy in the US for those interested in the history of medicine, particularly the evolving role in regulation, or lack thereof.


ORIGINAL ARTICLE

Shared Genetic Predisposition in Peripartum and Dilated Cardiomyopathies

Peripartum cardiomyopathy shares clinical features with idiopathic dilated cardiomyopathy, a disorder associated with mutations in more than 40 genes. This study shows that mutations in some of these genes, notably TTN, also have a strong association with this condition.


ORIGINAL ARTICLE

Eluxadoline for Irritable Bowel Syndrome with Diarrhea

http://www.nejm.org/doi/full/10.1056/NEJMoa1505180

In two randomized trials, eluxadoline was more effective than placebo in reducing abdominal pain and improving stool consistency in patients who had irritable bowel syndrome with diarrhea. Pancreatitis developed in 5 of 1666 patients (0.3%) who received eluxadoline.